• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.3
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• pp.347-358
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• 1993

Graft copolymerization of MMN4-VP onto cotton fiber using Ce(IV) salt as an initiator and triton X-100 as an emulsifier was performed under various polymerization conditions. In cograft polymerization, the polymeization behavior according to variation of 4-VP feed composition and the characteristics of MMA/4-VP graft polymer such as affinity for acid dye owing to cationization of cotton, antibacterial activity and thermal behavior were investigated. The results of this study were as follows : 1. While in copolymerization of MMA and 4-VP, 4-VP content in copolymer was more than that of monomer feed composition. 2. Increasing 4-VP content, graft yield was decreased, but graft efficiency was increased. In case of MMA/4-VP graft polymerization, the highest graft yield was obtained at higher CAN concentration than in MMA graft polymerization, the reason is that the behavior of 4-VP was disturbed by Ce(IV) sail 3. Elevation of temperature resulted in increase of graft yield and the apparent activation energy of MMA/4-VP graft polymerization was higher than that of MMA graft polymerization. 4. MMA/4-VP grafted cotton fiber showed affinity for acid dye, antibacterial activity and higher moisture regain than MMA grafted cotton fiber. MMA/4-VP grafted cotton fabric showed improvement of wrinkle recovery up to 40~50% graft yield and decreased thereafter. MMA/4-VP and MMA grafted cotton fabric did not showed significant difference in wrinkle recovery and stiffness.

• Journal of the Korean Society of Earth Science Education
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• v.11 no.2
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• pp.107-115
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• 2018

To learn the Earth's shape is a very important achievement standard in the earth science education. The purpose of this study is for helping school experiments by investigating effective experiments of the Earth's shape of each stage of school. Researchers suggest various experiment methods to learn the Earth's shape and investigated appropriate experiments to stage of elementary school, secondary school, high school and university for 26 pre-service teachers. As a result, there is difference between schools in effective experiments of the Earth's shape. Pre-service teachers thought that to observe a sail of ship to come back to a harbour is effective for elementary school students. And they responded that to compare the altitude of the polar star by latitudes is good for the secondary and high school students and to compare difference of sight according to height of the ground is effective for university students. They thought that level of the experiment method, abstract thinking and depth of background knowledge should be considered when teachers choose an effective experiment of the Earth's shape.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.55-60
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• 2007

Many electric power cables span the sea in Korean archipelago. Lots of shipping routes were established between the islands in the same area and ships frequently sail under the cable which cross the seas. Sometimes electric power cables were accidently broken by sailing ships and catastrophic damage of island industry followed thereby. If navigators have detailed knowledge about the height of electric power cable, the ship's sailing condition will be greatly improved. But at the present time, navigators have limited data about the electric power cable. Those are the horizontal distance between pylons, the height of pylons and minimum height of electric power cable. This study introduced the calculating methodology to find out the height of cable at any position between pylons. The ship's tracks were recorded and traffic safety was assessed by statistical method in relation to cable height.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.241-253
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• 2020

The Small-Unit Riverine Craft (SURC) is a small high-speed vessel used by navies and marine corps in relatively shallow waterway environments, such as riverine areas or littoral coasts. In the past, SURCs have primarily been rigid-hulled inflatable boats constructed using composite materials such as glass fiber reinforced plastics. More recently, single-hull SURCs have been manufactured using aluminum for weight reduction. In this study, a Carbon Fiber Reinforced Polymer (CFRP) material was applied instead to examine its feasibility in the basic design of an SURC with a hull length of 10 m. The CFRP structural design was obtained using the properties of a marine CFRP laminate, determined in a previous study. Next, the designed CFRP SURC was modeled to confirm its functionality, then compared with existing aluminum SURCs, indicating that the CFRP SURC was 41.49 % lighter, reduced fuel consumption by 30 %, and could sail 50 NM further for every hour of engine operation. A method for reducing the high cost of carbon fiber was also proposed based on the adjustment of the carbon fiber content to provide the optimum strength where required. The data developed in this study can be used as a basis for further design of CFRP craft.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.35
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• pp.71-98
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• 2007

UCP 600 approved at the Banking Commission Meeting of ICC at the end of October, 2006 comes into effect from July 1, 2007. The main revision of the UCP 600 concerning the sea transport document are as follows. First, if the bill of lading contains an on-board-notation, with the date of shipment, the date stated in the on-board-notation will be deemed the date of shipment. Secondly, phrases "on its face" and "otherwise authenticated" should be eliminated. Thirdly, when an agent signs for or signs on behalf of the master, there is no longer a need for the name of master to be quoted. Fourthly, the terminology "loading on-board or shipped on a named vessel" is changed to "shipped on-board a named vessel." Fifthly, phrases "the rejection of the documents transported only by sail" is removed. Finally, new rule in UCP is the signing of a charter party bill of lading by the charterer or a named agent on behalf of the charterer. My assessment of the revision in UCP 600 is as follows: Because a freight forwarder transport document is a weaker form than a liner bill of lading as collateral, banks may need a secure measure as to protect themselves from such a weak collateral effect. we recognize that Such a weak collateral effect stemmed from the elimination of rules in UCP 500 article 30, and the admission of transport documents issued by the freight forwarder as long as any one besides carrier, shipper, and charterer satisfies the requirements of transport document clauses in UCP 600. Finally, I hope the Commentary on UCP 600 will serve to explain the ambiguities remaining in the new rules.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.767-773
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• 2014

An economic ship routing means to sail a ship with a goal of minimizing the fuel consumption by utilizing weather forecast information, and there have been various systems which have been recently studied. For a successful economic ship routing system, it is needed to properly control an engine power or change a geographical path considering weather forecast. An optimal geographical path is difficult to be determined, though, because it is a minimal dynamic-cost path search problem where the actual fuel consumption is dynamically variable by the weather condition when the ship will pass the area. In this paper, we propose an geographical path-search algorithm based on evolutionary strategy to efficiently search a good quality solution out of tremendous candidate solutions. We tested our approach with the shortest path-based sailing method over seven testing routes and observed that the former reduced the estimated fuel consumption than the latter by 1.82% on average and the maximum 2.49% with little difference of estimated time of arrival. In particular, we observed that our method can find a path to avoid bad weather through a case analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.412-421
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• 2011

An economic ship routing means to sail a ship with a goal of minimizing the fuel consumption by utilizing weather forecast information, and many such systems have been recently developed. Most of them assume that sailing is carried out with a constraint like a fixed output of engine-power or a fixed sailing speed. However, if the output of engine-power is controlled, it is possible to reduce the fuel consumption by sailing a ship under a relatively good weather condition. In this paper, we propose a novel economic ship routing system which can search optimal outputs of the engine-power for each part of a path by employing an evolutionary strategy. In addition, we develope an $A^*$ algorithm to find the shortest path and a method to enhance the degree of curve representation. These make the proposed system applicable to an arbitrary pair of departure and destination points. We compared our proposed system with another existing system not controlling output of the engine-power over 36 scenarios in total, and observed that the former reduced the estimated fuel consumption than the latter by 1.3% on average and the maximum 5.6% with little difference of estimated time of arrival.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.435-438
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• 2009

A navigation aid buoy is a kind of safety facility for maritime navigation with a purpose of leading the vessels for navigating, docking and sail off. An advanced rechargeable battery is required for stable power supply for navigation aid buoy as the high magnitude LED lamps, real time location/control for navigation aids and e-Navigation support systems with maritime climate observation equipments have recently been deployed. This study is focused on the lithium battery, especially lithium polymer battery which is believed to be safer than the other types of batteries. The lithium polymer battery reviewed in this study is designed with $LiFePO_4$-based cathode, which has superior safety features to the oxide-based cathodes. Besides, a 3.6kWh battery pack has been built with the above-mentioned unit cells for the purpose of comparative research with lead acid battery system.

• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.524-529
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• 2018

Background: An increase in neutrophil gelatinase-associated lipocalin (NGAL) indicates tubular injury. Diabetic nephropathy causes typical changes in the kidney, characterized by glomerulosclerosis and eventual tubular damage. We validated the usefulness of plasma NGAL (pNGAL) as a biomarker of tubular damage in patients with diabetic nephropathy. Methods: We included 376 patients with diabetes mellitus (260 patients with chronic renal insufficiency who had not received hemodialysis and 116 hemodialyzed due to diabetic nephropathy) and 24 healthy controls. Patients with chronic renal insufficiency were divided into three groups according to urinary albumin excretion (UAE) levels. pNGAL levels were measured using the Triage NGAL test (Alere, San Diego, CA, USA) and were compared between groups. We also examined whether pNGAL level was related to the degree of albuminuria and cystatin C-based glomerular filtration rate (GFR). Results: Mean pNGAL levels of the healthy controls, chronic renal insufficiency patients with diabetes mellitus, and hemodialyzed patients were $61.9{\pm}5.3ng/mL$, $93.4{\pm}71.8ng/mL$, and $1,536.9{\pm}554.9ng/mL$, respectively. pNGAL level increased significantly in patients with severe albuminuria (P <0.001) and had a moderate correlation with the degree of albuminuria (r=0.467; P <0.001) and GFR (r=0.519; P <0.001). Multivariate regression analysis showed that the pNGAL level was associated with tubular damage independent of patient age, sex, and GFR. Conclusions: pNGAL level independently reflects the degree of tubular damage in patients with diabetic nephropathy. Measurement of pNGAL, combined with UAE, would enable simultaneous, highly reliable assessments of tubular damage for such patients.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.6
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• pp.423-431
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• 2022

In this paper, the results of Planar Motion Mechanism (PMM) test for a 1/15 scaled model of the MARIN Joubert BB2 submarine is dealt with to derive the maneuvering coefficients for surface condition. For the depth of surface navigation, the top of the sail was exposed 0.46 m above the water surface in the model scale, and it corresponds to 6.9 m in the full scale. The resistance and self-propulsion tests were conducted, and the model's self-propulsion point was obtained for 1.328 m/s, which corresponded to 10 knots in the full scale. The maneuvering tests were performed at the model's self-propulsion point, and the maneuvering coefficients were obtained. Based on the maneuvering coefficients, a turning simulation was performed for starboard 30 degree of stern fins. The straight-line stability and control effectiveness in the horizontal plane were analyzed using the maneuvering coefficients and compared with the appropriate range. For the analysis of the neutral fin angle of the X-type stern fin, the stern fin test with drift angles was carried out. As a result, the flow straightening effect at lower and upper parts of the stern fin was discussed.